1. Field of the Invention
This invention relates to the art of concentrically mounting thin wall hubs of driven members on drive shafts and specifically deals with the provision of shaft embracing embossments on a thin wall shaft receiving hub concentric with the hub axis to center the hub on the shaft regardless of clearances between the shaft and the shaft receiving aperture of the hub.
2. Prior Art
Heretofore mounting of thin wall fan blade hubs on drive shafts frequently presented a balancing problem brought about by eccentric misalignment of the blade hub axis and the drive shaft axis. In such installations the shaft has an end face or annular shoulder receiving the hub and a reduced diameter threaded stud portion projecting through a central aperture in the hub. A nut is then threaded on the stud portion to drivingly clamp the hub to the shaft. Such installations require clearance between the shaft and hub aperture permitting misalignment of the axis of the shaft and the axial center of the hub. In an attempt to minimize such misalignment the hubs were made sufficiently thick to accommodate a well receiving the shaft. Such installations were heavy and costly.
It would therefore be an improvement in this art to prevent misalignment of hubs on shafts without requiring massive thick hubs and it would especially be an improvement in this art to provide fan blade units with thin wall central hubs having raised shaft embracing rim portions lying in a circle centered on the axis of the fan blade unit around the shaft receiving aperture.
It would be a still further improvement in this art to emboss raised shaft embracing portions on thin wall hubs of fan blade units or the like to center the unit on the end of a drive shaft without increasing the thickness of the hub.